1. Field of the Invention
The present invention relates generally to systems and methods for cooling electronic components, and in particular to a heat transfer device having a chamber thermally coupled to the component and in fluid communication with a second chamber having hollow protrusions.
2. Description of the Related Art
High performance electronic devices typically generate large amounts of heat due to their power consumption requirements. To dissipate the heat generated from such devices a large heatsink is usually attached to their surface through a thermal interface material (TIM). In order to efficiently transmit heat from the device (or devices), which is usually a concentrated heat source, a heat sink is employed. Such heat sinks often consist of a large base structure that is highly conductive and a finned or pinned structure that is used to couple the thermal energy from the base structure to the cooling medium which is generally air. Ideally, the base structure should transmit the thermal energy with zero loss so that the finned or pinned structure which is much more efficient at transferring thermal energy to the cooling medium can operate at maximum efficiency. Thus, the base structure of a heat sink commonly utilizes copper or aluminum because these metals have excellent thermal conductivity, e.g., 200 to 400 W/m-K. However, in highly demanding cooling applications even the use of large base structures employing highly conductive metals is not adequate. In such cases, use is often made of vapor chambers to provide highly efficient distribution of heat from the concentrated heat source to the distributed fin structure. Such vapor chambers often have internal thermal conductivities exceeding 50,000 W/m-K. However, even though the heat may be efficiently transported to the fin structure using vapor chambers the individual pins or fins still have thermal conduction losses which reduce their ability to operate at maximum efficiency in transferring the thermal energy to the cooling medium. What is needed is a device that allows the flow of highly conductive cooling vapors between the pin/fin array and the vapor chamber to maximize the efficiency. The present invention satisfies that need.
To address the needs described above, the present invention discloses a heat transfer device wherein a vapor chamber is combined with a pin structure that allows the highly conductive cooling vapors to flow within the pins of a pin array maximizing the efficiency of both components of the heat sink into one unit. In one embodiment the heat transfer device comprises a thermally conductive chamber having a first thermally conductive chamber portion having a base thermally coupleable to a heat dissipating device; a second thermally conductive chamber portion having a plurality of hollow protrusions extending away from and in fluid communication with the first thermally conductive chamber portion wherein the thermally conductive chamber comprises a fluid vaporizable when in thermal communication with the heat dissipating device and condensable when in thermal communication with the hollow protrusions. The method comprises the steps of forming a first portion defining a thermally conductive chamber having a first thermally conductive chamber portion and a second thermally conductive chamber portion having a plurality of hollow protrusions extending away from and in fluid communication with the first thermally conductive chamber portion; inserting a wick structure in the first portion; coupling a base to the first portion; and inserting a working fluid into the thermally conductive chamber.
The present invention enables a highly efficient transmission of thermal energy from a concentrated heat source such as an electronic circuit assembly to an array of pin fins or other fin arrays that are designed to efficiently couple and transfer that energy to air or other vapors or fluids. This energy transference is accomplished by combining the prior art of vapor chambers and heatpipes into one efficient and economical assembly in which the thermal transmission to all surfaces of the pin array is accomplished with minimum thermal resistance, thus, maximizing the thermal transmission to the air or other vapors or fluids.